Mask apparatus and method for controlling the same

ABSTRACT

Provided is a mask apparatus. The mask apparatus includes a mask body in which a fan module is provided, a face guard coupled to a rear surface of the rear body so as to be in close contact with user&#39;s face and having a breathing space therein, a pressure sensor installed in the mask body to measure a pressure of the breathing space, and a controller configured to compare a current pressure value measured by the pressure sensor to a preset atmospheric pressure estimation, update the atmospheric pressure estimation based on a difference between the current pressure value and the atmospheric pressure estimation, and control a rotation speed of the fan module based on a difference between the updated atmospheric pressure estimation and the current pressure value.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119 and 35U.S.C. 365 to Korean Patent Application No. 10-2021-0094026 (filed onJul. 1, 2021), which is hereby incorporated by reference in itsentirety.

BACKGROUND

The present disclosure relates to a mask apparatus and a method forcontrolling the same.

A mask may be defined as a hygiene product that covers the user's noseand mouth to filter harmful substances including germs and dustcontained in the air when the user inhales and minimize spreads of virusor bad breath discharged when the user exhales to nearby people.

Recently, as the virus that is highly spreadable and highly contagioushas spread, it is recommended that individuals wear a mask to go out forsafety in order to minimize transmission.

Currently, various types and forms of masks are released in the market,and in particular, in order to minimize the harmful substances containedin the air from directly entering the mask wearer's respiratory tract, alot of masks equipped with a filter module are being sold.

Korean Patent Registration No. 10-1733470, which is a prior artdocument, (registration date: Apr. 28, 2017) discloses a pressuresensor-based electric respirator system having a real-time breathingcontrol function.

The prior art document discloses a technique to help breathing byprocessing data of the pressure sensor according to the breathing of theinhalation and exhalation through a microprocessor and by applying anoptimized algorithm to control the breathing in real time.

Particularly, a technique, in which a pressure in the respiratory tractis measured, and when a difference between an average pressure value andthe measured value is less than a reference value, it is determined asan inhalation to accelerate a fan, and when the difference between theaverage pressure value and the measured value is greater than areference value, it is determined as an exhalation to decelerate thefan, is disclosed.

However, the prior art document has the following limitations.

First, to acquire the average pressure value inside the respiratorytract, a breathing time of at least 2 cycles to 3 cycles is required, amemory capacity is required to store each pressure value, and acalculation time required to calculate the average pressure value istaken for a long time.

That is, in the case of the prior art document, when the mask is driven,a lot of basic data for obtaining a standard pressure average value isrequired, and thus, there is a limitation in that it is difficult toquickly control the fan according to the breathing characteristics. Ifthe fan control is not performed quickly, there is a limitation thatbreathing becomes rather uncomfortable.

Second, there is a limitation in that a breathing cycle and a breathingpattern are different for each user using the respiratory tract, andconsistency for each breathing cycle is deteriorated, and thus, it isdifficult to measure an accurate average pressure value. When a changein the surrounding environment (pressure change) occurs in the processof acquiring the average pressure value, it is difficult to reflect suchan error, and thus, there is a limitation in that it is difficult toaccurately determine an inhalation time and an exhalation time.

Third, when the change in the surrounding environment (pressure change)occurs in the process of acquiring the average pressure value, it isdifficult to reflect such an error, and thus, there is a limitation inthat it is difficult to accurately determine the inhalation time and theexhalation time. For example, when entering an elevator in which anatmospheric pressure is changed instantaneously, there is a limitationin that a calculation error occurs, and the fan is malfunctioned.

SUMMARY

Embodiments provide a mask apparatus capable of accurately determining abreathing state of a user by using an internal pressure of a mask, and amethod for controlling the same.

Embodiments also provide a mask apparatus capable of inferring a user'sbreathing state regardless of external environmental changes, and amethod for controlling the same.

Embodiments also provide a mask apparatus capable of providingsufficient air to a user in an inhaling state through atmosphericpressure estimation based on the internal pressure of the mask, and amethod for controlling the same.

Embodiments also provide a mask apparatus capable of quickly checking auser's breathing state without accumulating sufficient sensor datavalues.

In one embodiment, a mask apparatus includes: a mask body in which a fanmodule is provided; a face guard coupled to a rear surface of the rearbody so as to be in close contact with user's face and having abreathing space therein; a pressure sensor installed in the mask body tomeasure a pressure of the breathing space; and a controller configuredto: compare a current pressure value measured by the pressure sensor toa preset atmospheric pressure estimation; update the atmosphericpressure estimation based on a difference between the current pressurevalue and the atmospheric pressure estimation; and control a rotationspeed of the fan module based on a difference between the updatedatmospheric pressure estimation and the current pressure value.

That is, the breathing state may be determined using the internalpressure of the mask and the set atmospheric pressure estimation, andthe fan may be controlled according to the determined breathing state toassist the breathing.

Specifically, as a result of determining the breathing state, if it isan inhaling section, a rotation speed of the fan module may increase toallow air to flow into the inside from the outside. If it is an exhalingsection, breathing may be aided by reducing the rotation speed of thefan module or stopping the driving of the fan module.

In addition, in an embodiment, since the breathing state is determinedby estimating an atmospheric pressure based on the internal pressure ofthe mask, there may be an advantage in that the user's breathing stateis accurately inferred regardless of changes in the externalenvironment.

In addition, since the breathing state is estimated using only thecurrent mask pressure value and the preset atmospheric pressureestimation, there may be an advantage in that a large amount of data isnot required, and thus, memory consumption is reduced, and fan controlis quickly controlled.

The atmospheric pressure estimation may be a pressure value definedbetween a maximum pressure value and a minimum pressure value amongpressure values measured by the pressure sensor.

The atmospheric pressure estimation may be a pressure value definedbetween an atmospheric pressure maximum estimation and an atmosphericpressure minimum estimation, which are defined between the maximumpressure value and the minimum pressure value, among the pressure valuesmeasured by the pressure sensor.

That is, since the atmospheric pressure estimation is defined as a setvalue based on the pressure value measured by the pressure sensor, anerror may not occur due to a change in the external environment, andthus, there is an advantage of high reliability.

The controller may be configured to: compare each of a presetatmospheric pressure maximum estimation and a preset atmosphericpressure minimum estimation to the current pressure value; and updatethe atmospheric pressure estimation according to the comparison result.

When the preset atmospheric pressure maximum estimation is less than thecurrent pressure value, the controller may be configured to: update thepreset atmospheric pressure maximum estimation to the current pressurevalue; and update the preset atmospheric pressure minimum estimation byreflecting a weight.

When the preset atmospheric pressure maximum estimation exceeds thecurrent pressure value, the controller may be configured to compare thepreset atmospheric pressure minimum estimation to the current pressurevalue, and when the preset atmospheric pressure minimum estimation isequal to or greater than the current pressure value, the controller isconfigured to: update the preset atmospheric pressure minimum estimationto the current pressure value; and update the preset atmosphericpressure maximum estimation by reflecting a weight.

When the preset atmospheric pressure maximum estimation exceeds thecurrent pressure value, and the preset atmospheric pressure maximumestimation is less than the current pressure value, the controller maybe configured to update each of the preset atmospheric pressure maximumestimation and the preset atmospheric pressure maximum estimation byreflecting the weight.

The controller may be configured to update the updated atmosphericpressure maximum estimation to an intermediate value of the sum of theupdated atmospheric pressure maximum estimation and the updatedatmospheric pressure minimum estimation. Thus, an error range of theupdated atmospheric pressure estimation may be reduced, and reliabilitymay be improved.

When the updated atmospheric pressure estimation is greater than thecurrent pressure value, the controller may be configured to allow therotation speed of the fan module to increase, and when the updatedatmospheric pressure estimation is less than the current pressure value,the controller may be configured to allow the rotation speed of the fanmodule to decrease or stop an operation of the fan module. Thus, thereis an advantage in that the breathing becomes very comfortable becausethe appropriate fan is controlled according to the determined breathingstate.

A method for controlling a mask apparatus includes: measuring a currentpressure value with respect to a mask by using a pressure sensor;comparing the measured current pressure value to a preset atmosphericpressure estimation; update the atmospheric pressure estimation based ona difference between the current pressure value and the atmosphericpressure estimation; and controlling a rotation speed of a fan modulebased on a difference between the updated atmospheric pressureestimation and the current pressure value.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a mask apparatus according to an embodiment.

FIG. 2 is a rear perspective view of the mask apparatus.

FIG. 3 is an exploded perspective view of the mask apparatus.

FIG. 4 is a front perspective view of the mask apparatus from which afront body is separated.

FIG. 5 is a rear perspective view of a front body constituting the maskapparatus according to an embodiment.

FIG. 6 is a front perspective view of a rear body constituting the maskapparatus according to an embodiment.

FIG. 7 is a rear perspective view of the rear body.

FIG. 8 is a transverse cross-sectional view of the mask apparatusaccording to an embodiment.

FIG. 9 is a longitudinal cross-sectional view of the mask apparatus.

FIG. 10 is a schematic flowchart illustrating a method for controlling amask apparatus according to an embodiment.

FIG. 11 is a detailed flowchart illustrating the method for controllingthe mask apparatus according to an embodiment.

FIG. 12 is a graph showing a correlation between a current pressurevalue, an atmospheric pressure maximum estimation, an atmosphericpressure minimum estimation, and an atmospheric pressure estimation of amask according to an embodiment.

FIG. 13 is a graph in which the atmospheric pressure minimum estimationand the atmospheric pressure estimation are omitted from FIG. 12 .

FIG. 14 is a graph in which the atmospheric pressure maximum estimationand the atmospheric pressure estimation are omitted from FIG. 12 .

FIG. 15 is a graph in which the atmospheric pressure maximum estimationand the atmospheric pressure minimum estimation are omitted from FIG. 12.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings.

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration specific preferredembodiments in which the invention may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the invention, and it is understood that other embodiments maybe utilized and that logical structural, mechanical, electrical, andchemical changes may be made without departing from the spirit or scopeof the invention. To avoid detail not necessary to enable those skilledin the art to practice the invention, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense.

Also, in the description of embodiments, terms such as first, second, A,B, (a), (b) or the like may be used herein when describing components ofthe present invention. Each of these terminologies is not used to definean essence, order or sequence of a corresponding component but usedmerely to distinguish the corresponding component from othercomponent(s). It should be noted that if it is described in thespecification that one component is “connected,” “coupled” or “joined”to another component, the former may be directly “connected,” “coupled,”and “joined” to the latter or “connected”, “coupled”, and “joined” tothe latter via another component.

FIG. 1 is a front view of a mask apparatus according to an embodiment,FIG. 2 is a rear perspective view of the mask apparatus, FIG. 3 is anexploded perspective view of the mask apparatus, and FIG. 4 is a frontperspective view of the mask apparatus from which a front body isseparated.

Referring to FIGS. 1 to 4 , a mask apparatus 10 according to anembodiment includes a mask body 11, a face guard 14 that is fixedly ordetachably coupled to a rear surface of the mask body 11, and an aircleaning module 30 mounted inside the mask body 11.

In detail, the mask body 11 includes a front body 12 defining an outerappearance of a front surface and a rear body 13 coupled to a rearsurface of the front body 12 to define an outer appearance of a rearsurface. The front surface of the front body 12 defines a front surfaceof the mask apparatus 10, and the rear surface of the rear body 13 facesa face of a user (or a wearer).

In addition, the face guard 14 may be coupled to the rear surface of therear body 13 so as to be in close contact with the user's face and maybe made of a silicone or rubber material having elasticity. A breathingspace is defined inside the face guard 14, and when the user wears themask apparatus 10, a user's nose and mouth are accommodated in thebreathing space. Thus, external air purified while passing through theair cleaning module 30 is guided to the breathing space and inhales bythe user, and air generated when the user exhales is also dischargedinto the breathing space.

A predetermined space is defined between the front body 12 and the rearbody 13, and as illustrated in FIG. 4 , various electrical componentsare mounted on the front surface of the rear body 13. In addition, thevarious electrical components are shielded by the front body 12 so asnot to be exposed to the outside.

In addition, the air cleaning module 30 includes a fan module 31 placedin an accommodation portion 133 (see FIG. 6 ) provided in the rear body13 and a filter 33 placed behind the fan module 31. The fan module 31includes a centrifugal fan that suctions air in an axial direction todischarge the air in a radial direction.

The air cleaning module 30 further includes a filter housing 34 disposedbehind the filter 33, and a suction hole through which external air issuctioned is defined in the filter housing 34. The filter housing 34 maybe rotatably coupled to the rear body 13, and the suction hole may beprovided in the form of a suction grill 343 as illustrated in thedrawings.

In detail, the filter housing 34 includes a filter frame 341 surroundingthree side surfaces of the filter 33, and a filter cover 342 disposed ona rear surface of the filter frame 341. The filter cover 342 includes asuction grill 343.

The suction grill 343 may be understood as a structure including aplurality of suction slits 3431 and a plurality of partition ribs 3432disposed between the adjacent suction slits 343. The suction grill 343may be understood as a structure in which one large suction hole isdivided into a plurality of narrow and long suction slits 3431 by theplurality of partition ribs 3432. In addition, the plurality of narrowand long suction slits 3431 may be divided into an upper slit and alower slit by a reinforcing rib 3422. Hereinafter, the suction holedefined in the rear surface of the mask apparatus 10 to suction theexternal air is defined as including various types of holes includingthe suction grill 343, and the suction hole of the mask body 11 and thesuction grill 343 should be interpreted as the same meaning.

In addition, a discharge hole 101 is defined at a point spaced apartfrom the suction hole in a central direction of the rear body 13. Theexternal air suctioned through the suction hole or the suction grill 343by an operation of the fan module 31 sequentially passes through thefilter 33 and the fan module 31 and then is discharged into thebreathing space through the discharge hole 101.

The suction hole, i.e., the suction grill 343 is disposed outside theface guard 14, and the discharge hole 101 is disposed inside the faceguard 14. That is, the suction grill 343 is disposed outside thebreathing space, and the discharge hole 101 is defined inside thebreathing space, and thus, the suctioned external air and the airexhaled by the user are not mixed with each other.

The air cleaning module 30 further includes a flow guide 32 disposedbehind the fan module 31.

In addition, the mask apparatus 10 further includes at least one of amain control module 15, a power module 16, an indicator module 18, awireless communication module 17, a speaker module 19, and a battery 20,or an exhaust valve 21.

In detail, the main control module 15 is a module for controllingoperations of the fan module 31, the speaker module 19, and a pressuresensor and a microphone, which will be described later. The main controlmodule 15 may be disposed on an upper portion of a center of the frontsurface of the rear body 13.

The power module 16 is a control module for supplying power to theelectric components mounted on the mask apparatus 10. The power module16 may be disposed at a right lower end of the front surface of the rearbody 13.

A cable connector, into which a terminal of a cable for power supply anddata transmission is inserted, and an LED module used to inform anoperation state of the mask apparatus 10 may be mounted on the powermodule 16. Then, light irradiated from the LED module is diffused andguided through the indicator module 18 and then is emitted to theoutside of the mask apparatus 10.

The wireless communication module 17 may be any one of various types ofshort-range wireless communication modules including Bluetooth. Thewireless communication module 17 may be disposed on a left lower end ofthe front surface of the rear body 13. The wireless communication module17 may be mounted on the front surface of the rear body 13 in adirection crossing the rear body 13, for example, horizontally. Thewireless communication module 17 may be mounted on the front surface ofthe rear body 13 in a horizontal state by a pair of substrate insertionribs 1315 protruding from the front surface of the rear body 13. Bothside ends of the wireless communication module 17 are supported by thepair of substrate insertion ribs 1315.

The speaker module 19 may be disposed on the left lower end of the frontsurface of the rear body 13 corresponding to a lower side of thewireless communication module 17.

The battery 20 may be disposed at a center of the front surface of therear body 13, and the exhaust valve 21 may be disposed to shield anexhaust port provided below the center of the front surface of the rearbody 13. That is, when the user exhales, the exhaust valve 21 may openthe exhaust port, and when the user inhales, the exhaust valve 21 mayblock the exhaust port. The exhaust valve 21 may be bent and provided inthe form of a flat flap.

Here, it should be noted that the front, rear, left, and right sides ofthe mask body 11 are defined based on a state in which the user wearsthe mask apparatus 10.

FIG. 5 is a rear perspective view of the front body constituting themask apparatus according to an embodiment.

Referring to FIG. 5 , the front body 12 constituting the mask apparatus10 according to the embodiment defines an outer appearance of the frontsurface of the mask apparatus 10.

When the front surface of the front body 12 is provided as a single bodywithout a separate component mounted thereon, it has the advantage ofbeing clean in outer appearance. When the suction hole is defined ateach of the left and right sides of the front body 12, if the suctionhole is placed to face an upper side after taking off the mask apparatus10, there is disadvantage in that possibility, in which foreignsubstances are introduced into the mask apparatus 10 through the suctionhole, is high.

In addition, when a separate cover is installed to shield the suctionhole, thereby minimizing the inflow of the foreign substances, a gapneeds to be defined between an edge of the cover and the front surfaceof the front body 12 so that external air is introduced. That is, thereis a restriction that the separate cover has to be coupled to the frontsurface of the front body 12 in the form that protrudes from the frontsurface of the front body 12.

As a result, there is a high possibility that the separate cover isdamaged by external force or be separated from the front body 12 bybeing caught by a surrounding obstacle. For this reason, it isadvantageous in appearance to design the front body 12 so that thesuction hole for inhaling the external air is not defined as much aspossible to prevent a separate component from protruding due toadditional mounting of the separate component on the front surface ofthe front body 12, and also it is advantageous for securing durability.

In consideration of this aspect, the suction hole for suctioning theexternal air is not defined in the front surface of the front body 12according to the embodiment of the present invention, and also,additional components including the cover are not mounted at all, andthus, the front surface is designed so that a smooth and continuoussingle surface is provided. However, a speaker hole 123 is defined in aside of the lower portion so that user's voice is output to the outside.

A plurality of protrusion structures are disposed on the rear surface ofthe front body 12.

In detail, one or plurality of substrate fixing ribs 125 protrude froman upper end of the center of the rear surface of the front body 12. Theone or plurality of substrate fixing ribs 125 may press a front surfaceof the main control module 15 mounted on the rear body 13 when an edgeof the front body 12 is coupled to an edge of the front surface of therear body 13 to prevent the main control module 15 from beingoscillated.

A valve support rib 121 horizontally protrudes from the rear surface ofthe front body 12. The valve support rib 121 is disposed at a point atwhich an upper end of the exhaust valve 21 is disposed when the frontbody 12 is coupled to the rear body 13, to press an upper end of a frontsurface of the exhaust valve 21. For example, the valve support rib 121may have a predetermined width and extend backward by a predeterminedlength at a point spaced a predetermined distance downward from thecenter of the rear surface of the front body 12.

In addition, a pair of magnet pressing ribs 126 may protrude from therear surface of the front body 12. In detail, the face guard 14 ismounted on the rear surface of the rear body 13, a magnet is mounted ona front surface of the face guard 14, and a magnet that is attractive tothe magnet is mounted on the front surface of the rear body 13. As aresult, the face guard 14 is detachably mounted on the rear surface ofthe rear body 13 by the magnetic force of the magnet.

At this time, a pair of lower magnet mounting portions 135 (see FIG. 6 )for mounting the magnet are disposed on the front surface of the rearbody 13. In addition, the pair of magnet pressing ribs 126 function topress the pair of magnets mounted on the pair of lower magnet mountingportions 135, respectively.

In addition, a substrate pressing rib 127 that is in contact with afront end of a substrate constituting the wireless communication module17 protrudes from the rear surface of the front body 12. In detail, whenthe front body 12 and the rear body 13 are coupled to each other, thesubstrate pressing rib 127 presses the front end of the substrateconstituting the wireless communication module 17 to prevent thewireless communication module 17 from being oscillated or beingseparated from the substrate insertion rib 1315.

In addition, a support rib 122 supporting and surrounding an edge of thefront end of the speaker module 19 is disposed on the rear surface ofthe front body corresponding to an edge of the speaker hole 123. Thesupport rib 122 may be surrounded in a shape corresponding to a shape ofthe front surface of the speaker module 19.

In addition, a substrate fixing rib 124 for pressing a front surface ofthe power module 16 protrudes from the rear surface of the front body12. The substrate fixing rib 124 presses a front surface of thesubstrate constituting the power module 16 to prevent the power module16 from oscillated or being separated from the rear body 13.

FIG. 6 is a front perspective view of the rear body constituting themask apparatus according to an embodiment, and FIG. 7 is a rearperspective view of the rear body.

Referring to FIGS. 6 and 7 , the rear body 13 constituting the maskapparatus 10 according to the embodiment includes a face cover portion131 that covers a user's face and a fusion portion 132 bent forward froman edge of the face cover portion 131.

In detail, the fusion portion 132 is continuously disposed along an edgeof a top surface, edges of both surfaces, and an edge of a bottomsurface of the face cover portion 131. In addition, a width of thefusion portion 132 in a front and rear direction, which is bent along anedge of a bottom surface of the face cover portion 13 to extend forwardis the largest.

In the fusion portion 132, a portion disposed on the edge of the bottomsurface of the face cover portion 131 may be specifically defined as anextension protrusion. The extension protrusion has a convexly roundedshape in such a manner that a width in the front and rear directiongradually increases from both side ends of the rear body 13 toward thecenter.

A bottom surface exhaust hole 1362 is disposed at a center of the fusionportion 132 defined as the extension protrusion, and a button hole 1321is defined at a point spaced apart from the bottom exhaust port 1362toward a side end of the rear body 13. A power button is inserted intothe button hole 1321. An indication hole 1322 is defined at a pointspaced apart from each of left and right edges of the button hole 1321.

Light irradiated from a light emitting unit mounted on the power module16 is emitted to the outside through the pair of indication holes 1322.The light emitting unit includes an LED module.

When the light is emitted to the outside through any one of the pair ofindication holes 1322, it may mean that the power of the mask apparatus10 is turned on. In addition, a remaining amount of battery 20 may bepredicted according to a color of the light emitted through the otherone of the pair of indication holes 1322.

A terminal insertion hole 1323 is defined at a point further spacedapart from the button hole 1321 toward the side end of the rear body 13.A universal serial bus (USB) cable may be inserted into a terminalconnector provided in the power module 16 through the terminal insertionhole 1323. The battery 20 is charged through the USB cable, and aversion or function of the mask apparatus 10 may be updated or upgradedby data transmitted through the USB cable.

A accommodation portion 133 for accommodating the air cleaning module 30is provided in the rear body 13. The accommodation portion 133 isprovided at each of left and right sides from the center of the rearbody 13, and the pair of accommodation portions 133 are symmetrical withrespect to a vertical line passing through the center of the rear body13.

The accommodation portion 133 protrudes forward from the front surfaceof the face cover portion 131 to define a space in which the aircleaning module 30 is accommodated. The accommodation portion 133includes a seating surface 1331 on which the air cleaning module 30,specifically, the fan module 31 is seated, a coupling surface 1335connecting an outer edge of the seating surface 1331 at a side end ofthe face cover portion 131, and an air guide surface 1334 connecting thefront surface of the face cover portion 131 at an inner edge of theseating surface 1331.

In addition, the accommodation portion 133 further include a top surface1332 connecting upper ends of the seating surface, the air guide surface1334, and the coupling surface 1335 to the front surface of the facecover portion 131. In addition, the accommodation portion 133 furtherinclude a bottom surface 1332 connecting lower ends of the seatingsurface, the air guide surface 1334, and the coupling surface 1335 tothe front surface of the face cover portion 131.

One or more coupling units, for example, coupling hooks, are disposed onthe coupling surface 1335.

A fan mounting hole 1336 may be defined in the seating surface 1331, andthe top surface 1332 and the bottom surface 1334 may extend horizontallyand extend parallel to each other.

The coupling surface 1335 may be convexly rounded toward the outside ofthe rear body 13 and be inclined toward the center of the rear body 13from the face cover portion 131 to the seating surface 1331.

The air guide surface 1334 may be designed to extend convexly androundly from the seating surface 1331 toward the face cover portion 131so that air suctioned by the fan module 31 is smoothly guided toward thedischarge hole 101 along the air guide surface 1334.

As another example, the air guide surface 1334 is constituted by a roundportion that is rounded with a predetermined curvature at the inner edgeof the seating surface 1331 and an inclined portion connecting the facecover portion 131 flatly and obliquely at an end of the round portion.

The accommodation portion 133 includes a left accommodation portiondisposed at the left side from the center of the rear body 13 and aright accommodation portion disposed at the right side from the centerof the rear body 13. The left accommodation portion and the rightaccommodation portion are spaced a predetermined distance from thecenter of the rear body 13, and the battery 20 is mounted in a spacebetween the left accommodation portion and the right accommodationportion.

A battery mounting portion 138 may be disposed on the front surface ofthe rear body 13. In detail, the battery mounting portion 138 includes apair of battery seating ribs 1381 and a battery support rib 1382.

The pair of battery seating ribs 1381 protrude forward from the frontsurface of the face cover portion 131 or an edge of the air guidesurface 1334 to extend in parallel in the vertical direction. The pairof battery seating ribs 1381 supports a rear surface of the battery 20.

One end of the battery support rib 1382 extends from either one of theleft air guide surface 1334 and the right air guide surface 1334, andthe other end is connected to the other side of the left air guidesurface 1334 and the right air guide surface 1334.

The battery support rib 1382 has an n-shape to support the front andboth surfaces of the battery 20. Thus, a phenomenon in which the battery20 is separated from the rear body 13 may be prevented by the batterysupport rib 1382.

In addition, a central portion of the battery support rib 1382 protrudesforward so that a battery having a different size is selectivelymounted.

In detail, the battery support rib 1382 includes a pair of extensionportions extending forward from the pair of air guide surfaces 1334 anda connection portion extending in a horizontal direction to connect thepair of extension portions to each other.

In addition, a portion of the connection portion is bent to extendforward, so that the battery support rib 1382 is described as beingconstituted by a first battery support 1382 a and a second batterysupport 1382 b. In detail, the first battery support 1382 a may be usedto support a relatively wide and thin battery, and the second batterysupport 1382 b may be used to support a relatively narrow and thickbattery.

The second battery support 1382 b may be described as being provided bybending a portion of the connection portion constituting the firstbattery support 1382 a forward a plurality of times. Alternatively, itmay be described that the relatively small n-shaped second batterysupport 1382 b protrudes from a front surface of the relatively largen-shaped first battery support 1382 a.

An exhaust passage guide 136 protrudes forward from the front surface ofthe face cover portion 131 corresponding to a lower side of the batterymounting portion 138. In detail, the exhaust passage guide 136 isdisposed below the battery mounting portion 138, and a lower end of thebattery 20 mounted on the battery mounting portion 138 is supported by atop surface of the exhaust passage guide 136. As a result, it ispossible to prevent the battery 20 from being pulled downward due togravity while being inserted into the battery mounting portion 138.

The exhaust passage guide 136 may have a substantially tunnel-shapedlongitudinal cross-section, and a front exhaust port 1361 may bedisposed on the face cover portion 131 corresponding to the inside ofthe exhaust passage guide 136.

At least one of the front exhaust port 1361 or the bottom exhaust port1362 may be provided in the form of an exhaust grill divided into aplurality of small exhaust ports by a plurality of grills or partitionribs. In addition, the front exhaust port 1361 is selectively opened andclosed by the exhaust valve 21.

An upper magnet mounting portion 134 is disposed at the upper end of thecenter of the front surface of the face cover portion 131, and a pair oflower magnet mounting portions 135 are disposed on a lower end of thefront surface of the face cover portion 131.

In detail, the lower magnet mounting portion 135 is disposed on each ofa left edge and a right edge of the exhaust passage guide 136. Themagnet mounted on the lower magnet mounting portion 135 is pressed bythe pair of magnet pressing ribs 126 (see FIG. 5 ) protruding from therear surface of the front body 12.

A strap connection portion 137 is disposed at each of the left end andthe right end of the rear body 13. In detail, the strap connectionportion 137 is a portion to which an end of a strap or band that iscaught on the user's ear or wraps around the back of the user's head isconnected. The strap connection portion 137 is disposed at each of upperand lower portions of the left and right ends of the rear body 13.

Both ends of any one of the pair of straps may be respectively connectedto the strap connection portions 137 provided at the upper left andlower ends, and both ends of the other one may be respectively connectedto the strap connection portions 137 provided at the upper right andlower ends. Then, the pair of straps may be hung on both user's ears,respectively.

As another method, both ends of any one of the pair of straps may berespectively connected to the strap connection portions 137 provided atthe upper left and right ends, and both ends of the other one may berespectively connected to the strap connection portions 137 provided atthe lower left and right ends. Then, the pair of straps may be wrappedaround the user's back of the head.

Each of the four strap connection portions 137 includes a strap groove1373 that is recessed from the front surface of the rear body 13 toextend in the horizontal direction (width direction of the rear body), astrap hole 1374 defined in any point of the strap groove 1373, a strapbar 1372 connecting top and bottom surfaces of the strap groove 1373 toeach other, and a tubular waterproof rib 1371 extending from the rearsurface of the rear body 13 corresponding to an edge of the strap hole1374.

A main control module mounting portion 139 is disposed on the frontsurface of the rear body 13.

In detail, the main control module mounting portion 139 includes asubstrate fixing hook 1391 protruding forward from the front surface ofthe face cover portion 131 and a substrate seating rib 1393 andsubstrate support rib 1392, which support a rear surface of the maincontrol module 13.

In detail, the substrate fixing hook 1391 may include a pair of firstsubstrate fixing hooks 1391 a disposed above the accommodation portion133 and a pair of second fixing hooks 1391 b disposed between the pairof accommodation portions 133 facing each other.

The pair of first substrate fixing hooks 1391 a may be disposed at apoint spaced upward from a top surface of the left accommodation portionand at a point spaced upward from a top surface of the rightaccommodation portion. The pair of first substrate fixing hooks 1391 afunction to fix left and right ends of the main control module 15.

In addition, the pair of second substrate fixing hooks 1391 b may berespectively disposed at points corresponding to inner upper ends of thepair of accommodation portions 133. In detail, any one of the pair ofsecond substrate fixing hooks 1391 b may be disposed at a point at whichan upper edge of the right accommodation portion meets the front surfaceof the face cover portion 131. In addition, the other of the pair ofsecond substrate fixing hooks 1391 b may be disposed at a point at whichan upper edge of the left accommodation portion meets the front surfaceof the face cover portion 131.

The pair of second substrate fixing hooks 1391 b function to fix a lowerend of the control substrate constituting the main control module 15.

In addition, the substrate seating rib 1392 may protrude from the frontsurface of the face cover portion 131 corresponding between the pair ofsecond substrate fixing hooks 1391 b to support a rear surface of thelower end of the control substrate constituting the main control module15.

In addition, a rear surface of the upper end of the main control module15 may be supported by a front end of the upper magnet mounting portion134. The main control module 15 is disposed to be spaced apart from theface cover portion 131 by the upper magnet mounting portion 134 and thesubstrate seating rib 1393, and thus, there is an effect that the maincontrol module 15 is stably coupled to the rear body without oscillatedby the substrate fixing hook 1391.

A pressure sensor mounting portion (or breathing sensor mountingportion) 130 may be disposed at a center of the upper portion of thefront surface of the face cover portion 131. A pressure sensor (to bedescribed later) mounted on the pressure sensor mounting portion 130senses a pressure in the breathing space defined inside the face guard14. That is, it may be determined whether the user is currently inhalingor exhaling according to a change in pressure inside the breathingspace. The pressure sensor may be defined as a breathing sensor, andalthough the terms are different, it should be understood as a sensorperforming the same function.

The pressure sensor mounting portion 130 is provided on the frontsurface of the rear body 13, and when the main control module 15 ismounted on the main control module mounting portion 139, the pressuresensor mounting portion 130 is disposed at a point at which the pressuresensor (or breathing sensor) mounted on the rear surface of the maincontrol module 15 is disposed. Thus, when the main control module 15 ismounted to the main control module mounting portion 139, the pressuresensor is accommodated in the pressure sensor mounting portion 130. Inaddition, a front end of the pressure sensor mounting portion 130 is inclose contact with the rear surface of the control substrate of the maincontrol module 15.

In addition, a portion defining a bottom of the pressure sensor mountingportion 130 protrudes to a rear side of the rear body 13, and athrough-hole 1301 is defined in a bottom surface of the portionprotruding backward. The breathing space defined by the rear surface ofthe rear body 13 and the face guard 14 and an inner space of thepressure sensor mounting portion 130 communicate with each other throughthe through-hole 1301. As a result, a portion of air generated when theuser exhales flows into the inner space of the pressure sensor mountingportion 130 through the through-hole 1301. In addition, the pressuresensor accommodated in the pressure sensor mounting portion 130 senses apressure inside the pressure sensor mounting portion 130. Then, thesensed pressure value is transmitted to a microcomputer (to be describedlater) of the main control module 15 so that a user's breathing state isdetermined.

A magnet mounting groove 1314 is defined each of the rear surface of therear body 13 corresponding to a direct rear surface of the upper magnetmounting portion 134 and the rear surface of the rear body 13corresponding to a direct rear surface of the pair of lower magnetmounting portions 135.

The magnet mounting groove 1314 includes a first magnet mounting groove1311 defined in a direct rear surface of the upper magnet mountingportion 134 and a second magnet mounting groove 1312 and a third magnetmounting groove 1313, which are defined in a direct rear surface of thelower magnet mounting portion 134.

Three magnets mounted on the face guard 14 are attached to the first tothird magnet mounting grooves 1311 to 1313 by magnetic force,respectively. In addition, when the user pulls the face guard 14 withforce greater than the magnetic force, the face guard 14 is easilyseparated from the rear body 13.

As described above, the fan mounting hole 1336 may be defined in theseating surface 1331 constituting the accommodation portion 133. Inaddition, one or plurality of flow guide coupling holes 1331 a aredefined at a point spaced apart from the fan mounting hole 1336 towardthe outer edge of the seating surface 1331. The flow guide 32 is fixedto the accommodation portion 133 by a coupling member passing throughthe flow guide coupling hole 1331 a.

In addition, a flow guide hook 1339 and a filter hook 1338 are disposedto be spaced apart from each other in the front and rear direction onthe coupling surface 1335 constituting the accommodation portion 133.The flow guide hook 1339 is disposed closer to the seating surface 1331than the filter hook 1338.

In addition, a gripping groove 1337 is defined at a side end of the rearsurface of the rear body 13 corresponding to a rear side of the filterhook 1338. In detail, it may be described that the gripping groove 1337is defined at a point at which the fusion portion 132 and the couplingsurface 1335 meet each other.

FIG. 8 is a transverse cross-sectional view of the mask apparatusaccording to an embodiment, and FIG. 9 is a longitudinal cross-sectionalview of the mask apparatus.

Referring to FIGS. 8 and 9 , when the user operates the fan module 31 bypressing the power button, external air is introduced into the maskapparatus 10 through the suction grills 343 (or suction holes) disposedat the left and right sides of the rear surface of the mask apparatus10.

The external air introduced through the suction grill 343 is purifiedwhile passing through the filter 33. Then, the air passing through thefilter 33 is suctioned in an axial direction of the fan module 31 andthen discharged in a radial direction.

As illustrated in FIG. 8 , a front surface of the fan module 31 isseated on the seating surface 1331, and a rear surface of the fan module31 is opened. In addition, the opened rear surface of the fan module 31is shielded by the flow guide 32, and a communication hole serving as ansuction hole of the fan module 31 is defined in the flow guide 32. Theair passing through the filter 33 is introduced into the fan through thecommunication hole.

Also, an air duct 102 is defined between a side surface of the flowguide 32 and the air guide surface 1334. In addition, an inlet of theair duct 102 communicates with an outlet (or discharge hole) of the fanmodule 31, and the outlet of the air duct 102 communicates with thedischarge hole 101.

In addition, the discharge hole 101 is defined in the breathing spacedefined by the rear surface of the face guard 14 and the rear body 13.Therefore, the external air suctioned by the fan module 31 is dischargedto the breathing space, so that the user inhales.

In addition, the air guide surface 1334 is provided to be smoothlyrounded from the outlet of the fan module 31 toward the discharge hole101, so that the air discharged in the radial direction of the fanmodule 31 is not sharply changed in flow direction while flowing towardthe discharge hole 101.

In detail, in the case of the centrifugal fan, the discharge of the airin the axial suction and radial discharge are due to a shape of a coneor truncated cone hub. That is, the air suctioned in the axial directionof the centrifugal fan is smoothly changed in direction to 90 degreesalong the round surface of the hub.

Here, since the rounded direction of the hub constituting the fan module31 and the rounded direction of the air guide surface 1334 are the same,the air suctioned into the fan module 31 smoothly flows in only onedirection.

If the suction grill 343 is provided on the front body 12, the suctionhole of the fan module 31 faces the front body 12, and as a result, therounded direction of the hub constituting the fan module is opposite tothe rounded direction of the air guide surface 1334. As a result, theair discharged from the fan module 31 collides with the beginning of theair guide surface 1334 corresponding to the suction hole of the air duct102 to generate flow resistance and flow noise.

That is, the air suctioned in the axial direction of the fan module 31substantially generates an S-shaped flow, resulting in a greater flowloss than the structure, in which the C-shaped or n-shaped flow isgenerated, according to an embodiment.

When the user exhales, the air discharged through the user's mouth andnose is collected in the breathing space. A minute portion of the aircollected in the breathing space is introduced into the pressure sensormounting portion 130 through the through-hole 1301.

In addition, most of the air collected in the breathing space descendsand is discharged to the outside through the front exhaust port 1361 andthe bottom exhaust port 1362. Here, as the exhaust valve 20 is bentforward by the pressure of air generated when the user exhales, thefront exhaust port 1361 is opened. In addition, when the user inhales,the pressure inside the breathing space is lower than an atmosphericpressure, and the exhaust valve 20 returns to its original position toshield the front exhaust port 1361.

FIG. 10 is a schematic flowchart illustrating a method for controlling amask apparatus according to an embodiment.

Referring to FIG. 10 , a mask apparatus 10 measures a current pressurevalue of a mask using a pressure sensor 220.

The pressure sensor may be mounted on a pressure sensor mounting portion130 disposed on a mask body 11. At least a portion of the pressuresensor may be disposed inside the pressure sensor mounting portion 130to sense a pressure of a breathing space.

Here, the current pressure value of the mask may mean a pressure of thebreathing space defined by the user's face and the face guard 14.

The pressure sensor may be an air pressure sensor that measures apressure or air pressure in a sealed space using a flow rate or windstrength of introduced air. Alternatively, the pressure sensor may be adifferential pressure sensor that measures a pressure change in a sealedspace.

The mask apparatus 10 compares the measured current pressure value tothe atmospheric pressure estimation and updates the atmospheric pressureestimation based on a difference between the current pressure value andthe atmospheric pressure estimation.

The mask apparatus 10 may compare the current pressure value measured bythe pressure sensor to a preset atmospheric pressure estimation andupdate the current atmospheric pressure estimation based on thedifference.

The atmospheric pressure estimation may be an intermediate value definedbetween a maximum pressure value and a minimum pressure value amongpressure values measured for a predetermined time by the pressuresensor. That is, the atmospheric pressure estimation may be changed orupdated in real time according to the pressure value measured by thepressure sensor. Therefore, there is an advantage of high reliabilitybecause an error does not occur due to changes in the externalenvironment (S12 and S13).

The mask apparatus 10 controls a rotation speed of the fan module 31based on a difference between the updated atmospheric pressureestimation and the current pressure value.

When the updated atmospheric pressure estimation is greater than thecurrent pressure value, the mask apparatus 10 may determine that theuser's breathing state is an inhaling state, and a rotation speed of thefan module 31 increases.

In addition, the updated atmospheric pressure estimation is less thanthe current pressure value, the mask apparatus 10 may determine that theuser's breathing state is an exhaling state, and the rotation speed ofthe fan module 31 decreases.

FIG. 11 is a detailed flowchart illustrating the method for controllingthe mask apparatus according to an embodiment.

Referring to FIG. 11 , when power of the mask apparatus 10 is turned on,the fan module 31 operates at a low speed.

When the power of the mask apparatus 10 is turned on, the fan module 31may operate. In this case, the fan module 31 may perform a low-speedoperation with a relatively low rotation speed.

The reason why each of the fan modules 16 and 17 operates at the lowspeed is not only to facilitate the user's breathing, but also to removemoisture or water vapor from the inside of the mask apparatus 10.

If the fan module 31 operates at a high speed, a pressure value sensedby the pressure sensor may become unstable due to air resistance causedby the high-speed rotation of the fan module 31. That is, to increase insensor accuracy of the pressure sensor, the fan module 31 may operate ata low speed (S21 and S22).

The mask apparatus 10 measures a current pressure value of the maskusing the pressure sensor and compares the measured current pressurevalue to a previous atmospheric pressure estimation.

The atmospheric pressure estimation may be an intermediate value definedbetween a maximum pressure value and a minimum pressure value amongpressure values measured for a predetermined time by the pressuresensor.

The atmospheric pressure estimation may be updated in real time byfollowing the current pressure value. The current atmospheric pressureestimation may be updated based on a preset atmospheric pressureestimation and a current pressure value. The updated atmosphericpressure estimation may be accumulated and stored in a memory of themask apparatus 10.

In this embodiment, the atmospheric pressure estimation may be set as anintermediate value of the sum of an atmospheric pressure maximumestimation and an atmospheric pressure minimum estimation. Theatmospheric pressure maximum estimation and the atmospheric pressureminimum estimation may be updated by following or converging the currentpressure value. Thus, an error range of the updated atmospheric pressureestimation may be reduced, and reliability may be improved.

The mask apparatus 10 may compare each of the preset atmosphericpressure maximum estimation and the preset atmospheric pressure minimumestimation to the current pressure value and update the currentatmospheric pressure estimation based on the difference (S23 and S24).

Hereinafter, a correlation between the current pressure value, theatmospheric pressure maximum estimation, the atmospheric pressureminimum estimation, and the atmospheric pressure estimation will bedescribed with reference to the drawings.

FIG. 12 is a graph showing the correlation between the current pressurevalue, the atmospheric pressure maximum estimation, the atmosphericpressure minimum estimation, and the atmospheric pressure estimation ofa mask according to an embodiment, FIG. 13 is a graph in which theatmospheric pressure minimum estimation and the atmospheric pressureestimation are omitted from FIG. 12 , FIG. 14 is a graph in which theatmospheric pressure maximum estimation and the atmospheric pressureestimation are omitted from FIG. 12 , and FIG. 15 is a graph in whichthe atmospheric pressure maximum estimation and the atmospheric pressureminimum estimation are omitted from FIG. 12 .

Referring to FIGS. 12 to 15 , a horizontal axis of the graph indicatesthe passage of time, and a vertical axis of the graph indicates anamount of change in pressure. In FIGS. 12 to 15 , a dotted line Sindicates a current pressure value, a thick solid line H indicates anatmospheric pressure maximum estimation, a thin solid line L indicatesan atmospheric pressure minimum estimation, and a dashed-dotted line Aindicates an atmospheric pressure estimation.

Referring to FIGS. 12 to 15 , a graph of the sensor pressure value Smeasured by the pressure sensor draws a sine wave according to aperson's breathing cycle, i.e., inhalation and exhalation.

For example, the sensor pressure value S decreases in an inhaling statein which the user inhales, and the sensor pressure value S increases inan exhalation state in which the user exhales.

The sensor pressure value S may have maximum pressure values H1, H2, andH3 and minimum pressure values L1, L2, and L3 according to eachbreathing cycle.

In an embodiment, an atmospheric pressure maximum estimation and anatmospheric pressure minimum estimation may be updated by following themaximum pressure values H1, H2, and H3 and the minimum pressure valuesL1, L2, and L3 of the sensor pressure value S, and the atmosphericpressure estimation may be updated based on the updated atmosphericpressure maximum estimation and the atmospheric pressure minimumestimation.

Specifically, the mask apparatus 10 determines whether the presetatmospheric pressure maximum estimation is equal to or less than thecurrent pressure value. Here, if the preset atmospheric pressure maximumestimation is equal to or less than the current pressure value, thepreset atmospheric pressure maximum estimation is updated to the currentpressure value, and the preset atmospheric pressure minimum estimationis updated by reflecting a weight.

When it is determined that the preset atmospheric pressure maximumestimation is equal to or less than the current pressure value, thepreset atmospheric pressure maximum estimation may follow the currentpressure value. That is, when it is determined that the presetatmospheric pressure maximum estimation is equal to or less than thecurrent pressure value, the preset atmospheric pressure maximumestimation may increase along the current pressure value and then may bethe same as the current pressure value.

Here, when the preset atmospheric pressure maximum estimation is equalto or less than the current pressure value, a period (time point) inwhich the atmospheric pressure maximum estimation is updated to thecurrent pressure value may be defined as first update periods R1 and R2(S25 and S26).

When the preset atmospheric pressure maximum estimation exceeds thecurrent pressure value, the mask apparatus 10 determines whether thepreset atmospheric pressure minimum estimation is equal to or greaterthan the current pressure value. Here, if the preset atmosphericpressure minimum estimation is equal to or greater than the currentpressure value, the preset atmospheric pressure minimum estimation isupdated to the current pressure value, and the preset atmosphericpressure minimum estimation is updated by reflecting a weight.

When it is determined that the preset atmospheric pressure minimumestimation is equal to or greater than the current pressure value, thepreset atmospheric pressure minimum estimation may follow the currentpressure value. That is, when it is determined that the presetatmospheric pressure minimum estimation is equal to or greater than thecurrent pressure value, the preset atmospheric pressure minimumestimation may decrease along the current pressure value and then may bethe same as the current pressure value.

Here, when the preset atmospheric pressure minimum estimation is equalto or greater than the current pressure value, a period (time point) inwhich the atmospheric pressure minimum estimation is updated to thecurrent pressure value may be defined as second update periods R3, R4,and R5.

Here, the first update periods R1 and R2 and the second update periodsR3, R4, and R5 do not overlap each other (S27 and S28).

When the preset atmospheric pressure maximum estimation exceeds thecurrent pressure value, and the preset atmospheric pressure maximumestimation is less than the current pressure value, each of the presetatmospheric pressure maximum estimation and the preset atmosphericpressure maximum estimation may be updated by reflecting the weight.

In detail, when the atmospheric pressure maximum estimation is notupdated by following the current pressure value, the mask apparatus 10may update the atmospheric pressure maximum estimation to converge tothe preset atmospheric pressure estimation by reflecting the weight.

According to this embodiment, Equation for updating the atmosphericpressure maximum estimation by reflecting the weight is as follows.

(APME)_(n)=(APME)_(n−1)−((APME)_(n−1)−(APE)_(n−1))×Weight  [Equation 1]

In Equation 1, “APME” may indicate an atmospheric pressure maximumestimation, “APE” may indicate an atmospheric pressure estimation, and“Weight” may indicate a preset weight.

The “Weight” may be a preset constant and may be a reciprocal number ofa value obtained by multiplying a person's “maximum breathing time(sec)” and “sensor update period (Hz)”.

For example, the maximum breathing time may be about 4 seconds, and thesensor update cycle may be about 75 Hz. However, an embodiment of thepresent disclosure is not limited thereto, and the maximum breathingtime and the sensor update period may be set in various manners.

In addition, according to this embodiment, Equation for updating theatmospheric pressure minimum estimation by reflecting the weight is asfollows.

(APNE)_(n)=(APNE)_(n−1)+((APE)_(n−1)−(APNE)_(n−1))×Weight  [Equation 2]

In Equation 2, “APNE” may indicate an atmospheric pressure minimumestimation, “APE” may indicate an atmospheric pressure estimation, and“Weight” may indicate a preset weight.

The “Weight” may be a preset constant and may be a reciprocal number ofa value obtained by multiplying a person's “maximum breathing time(sec)” and “sensor update period (Hz)”.

For example, the maximum breathing time may be about 4 seconds, and thesensor update cycle may be about 75 Hz. However, an embodiment of thepresent disclosure is not limited thereto, and the maximum breathingtime and the sensor update period may be set in various manners.

As described above, an n-th atmospheric pressure maximum estimation maybe updated based on an (n−1)-th atmospheric pressure maximum estimationand an (n−1)-th atmospheric pressure estimation, and the n-thatmospheric pressure minimum estimation may be updated based on the(n−1)-th atmospheric pressure minimum estimation and the (n−1)-thatmospheric pressure estimation.

Therefore, to update the atmospheric pressure estimation, since only thecurrent pressure value and the previous atmospheric pressure estimationdata are required, there is an advantage in that a memory capacity fordata accumulation is minimized, and a data processing time is reduced.

Here, a period (time point) in which the atmospheric pressure maximumestimation is updated to converge to the atmospheric pressure estimationmay be defined as first convergence periods W1, W2, and W3, and a period(time point) in which the atmospheric pressure minimum estimation isupdated to converge to the atmospheric pressure estimation may bedefined as second convergence periods W4 and W5.

In summary, when each of the atmospheric pressure maximum estimation andthe atmospheric pressure minimum estimation meets a predeterminedcondition, the mask apparatus 10 may update the atmospheric pressuremaximum estimation and the atmospheric pressure minimum estimation byfollowing the current pressure value, and when each of the atmosphericpressure maximum estimation and the atmospheric pressure minimumestimation does not meet the predetermined condition, weights(application of Equations 1 and 2) may be reflected in the atmosphericpressure maximum estimate and the atmospheric pressure minimum estimateso as to be updated to converge to the atmospheric pressure estimation(S27 and S29).

As described in the operations S24 to S29, when the atmospheric pressuremaximum estimation and the atmospheric pressure minimum estimation areupdated, the mask apparatus 10 updates an intermediate value of the sumof the updated atmospheric pressure maximum estimation and the updatedatmospheric pressure minimum estimation as the atmospheric pressureestimation.

That is, the preset atmospheric pressure estimation may be updated asthe intermediate value between the recently updated atmospheric pressuremaximum estimation and the updated atmospheric pressure minimumestimation (S30).

The mask apparatus 10 controls a rotation speed of the fan module 31based on a difference between the updated atmospheric pressureestimation and the current pressure value.

As illustrated in FIG. 15 , when the updated atmospheric pressureestimation A is greater than the sensor pressure value S, the maskapparatus 10 may determine that the user's breathing state is in theinhaling states N1, N2, N3, N4, N5, and N6, and thus, the rotation speedof the fan may increase.

That is, when it is determined that the user is in the inhaling state,the rotation speed of the fan module 31 may increase to help thebreathing (inhalation).

In addition, when the updated atmospheric pressure estimation A is lessthan the sensor pressure value S, the mask apparatus 10 may determinethat the user's breathing state is in the exhaling states E1, E2, E3,E4, and E5, and thus, the rotation speed of the fan may decrease (S31).

That is, when it is determined that the user is in the exhaling state,the rotation speed of the fan module 31 may decrease to help thebreathing (exhalation).

According to the constituents as described above, following effects maybe expected.

First, the breathing state may be determined using the internal pressureof the mask and the set atmospheric pressure estimate, and since the fanis controlled according to the determined breathing state to assist thebreathing, there is an advantage of making breathing easier.

Second, since the atmospheric pressure estimation is estimated based onthe pressure value measured in the mask, and the user's breathing stateis determined by comparing the atmospheric pressure estimation to thecurrent pressure value, there is an advantage of being able toaccurately determine the breathing state regardless of changes in theexternal environment.

Third, to update the atmospheric pressure estimation, since only thecurrent pressure value and the previous atmospheric pressure estimationare required, a memory capacity for data accumulation may be minimized,and a data processing time may be reduced. Therefore, there is anadvantage that it is possible to quickly determine the breathing stateand the cost becomes low.

Fourth, since the atmospheric pressure estimation is updated in realtime, and the rotation speed of the fan module is automatically adjustedbased on the difference between the updated atmospheric pressureestimation and the current pressure value, there is an advantage in thatthe user's breathing becomes easier, and the convenience of use isimproved.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A mask apparatus comprising: a mask body in whicha fan module is provided; a face guard coupled to a rear surface of therear body so as to be in close contact with user's face and having abreathing space therein; a pressure sensor installed in the mask body tomeasure a pressure of the breathing space; and a controller configuredto: compare a current pressure value measured by the pressure sensor toa preset atmospheric pressure estimation; update the atmosphericpressure estimation based on a difference between the current pressurevalue and the atmospheric pressure estimation; and control a rotationspeed of the fan module based on a difference between the updatedatmospheric pressure estimation and the current pressure value.
 2. Themask apparatus according to claim 1, wherein the atmospheric pressureestimation is a pressure value defined between a maximum pressure valueand a minimum pressure value among pressure values measured by thepressure sensor.
 3. The mask apparatus according to claim 2, wherein theatmospheric pressure estimation is a pressure value defined between anatmospheric pressure maximum estimation and an atmospheric pressureminimum estimation, which are defined between the maximum pressure valueand the minimum pressure value, among the pressure values measured bythe pressure sensor.
 4. The mask apparatus according to claim 1, whereinthe controller is configured to: compare each of a preset atmosphericpressure maximum estimation and a preset atmospheric pressure minimumestimation to the current pressure value; and update the atmosphericpressure estimation according to the comparison result.
 5. The maskapparatus according to claim 4, wherein, when the preset atmosphericpressure maximum estimation is less than the current pressure value, thecontroller is configured to: update the preset atmospheric pressuremaximum estimation to the current pressure value; and update the presetatmospheric pressure minimum estimation by reflecting a weight.
 6. Themask apparatus according to claim 5, wherein, when the presetatmospheric pressure maximum estimation exceeds the current pressurevalue, the controller is configured to compare the preset atmosphericpressure minimum estimation to the current pressure value, and when thepreset atmospheric pressure minimum estimation is equal to or greaterthan the current pressure value, the controller is configured to: updatethe preset atmospheric pressure minimum estimation to the currentpressure value; and update the preset atmospheric pressure maximumestimation by reflecting a weight.
 7. The mask apparatus according toclaim 6, wherein, when the preset atmospheric pressure maximumestimation exceeds the current pressure value, and the presetatmospheric pressure maximum estimation is less than the currentpressure value, the controller is configured to update each of thepreset atmospheric pressure maximum estimation and the presetatmospheric pressure maximum estimation by reflecting the weight.
 8. Themask apparatus according to claim 7, wherein the controller isconfigured to update the updated atmospheric pressure maximum estimationto an intermediate value of the sum of the updated atmospheric pressuremaximum estimation and the updated atmospheric pressure minimumestimation.
 9. The mask apparatus according to claim 8, wherein, whenthe updated atmospheric pressure estimation is greater than the currentpressure value, the controller is configured to allow the rotation speedof the fan module to increase.
 10. The mask apparatus according to claim8, wherein, when the updated atmospheric pressure estimation is lessthan the current pressure value, the controller is configured to allowthe rotation speed of the fan module to decrease or stop an operation ofthe fan module.
 11. A method for controlling a mask apparatus, themethod comprising: measuring a current pressure value with respect to amask by using a pressure sensor; comparing the measured current pressurevalue to a preset atmospheric pressure estimation; updating theatmospheric pressure estimation based on a difference between thecurrent pressure value and the atmospheric pressure estimation; andcontrolling a rotation speed of a fan module based on a differencebetween the updated atmospheric pressure estimation and the currentpressure value.
 12. The method of claim 11, wherein the atmosphericpressure estimation is a pressure value defined between a maximumpressure value and a minimum pressure value among pressure valuesmeasured by the pressure sensor.
 13. The method of claim 12, wherein theatmospheric pressure estimation is a pressure value defined between anatmospheric pressure maximum estimation and an atmospheric pressureminimum estimation, which are defined between the maximum pressure valueand the minimum pressure value, among the pressure values measured bythe pressure sensor.
 14. The method of claim 11, wherein the comparingof the measured current pressure value to the atmospheric pressureestimation comprises comparing each of a preset atmospheric pressuremaximum estimation and a preset atmospheric pressure minimum estimationto the current pressure value.
 15. The method of claim 14, wherein theupdating of the atmospheric pressure estimation based on the differencebetween the current pressure value and the atmospheric pressureestimation comprises: when the preset atmospheric pressure maximumestimation is less than the current pressure value, updating the presetatmospheric pressure maximum estimation to the current pressure value;and updating the preset atmospheric pressure minimum estimation byreflecting a weight.
 16. The method of claim 15, further comprising:comparing the preset atmospheric pressure minimum estimation to thecurrent pressure value when the preset atmospheric pressure maximumestimation exceeds the current pressure value; and updating the presetatmospheric pressure minimum estimation to the current pressure value toupdate the preset atmospheric pressure maximum estimation by reflectinga weight when the preset atmospheric pressure minimum estimation isequal to or greater than the current pressure value.
 17. The method ofclaim 16, further comprising, when the preset atmospheric pressuremaximum estimation exceeds the current pressure value, and the presetatmospheric pressure maximum estimation is less than the currentpressure value, updating each of the preset atmospheric pressure maximumestimation and the preset atmospheric pressure maximum estimation byreflecting the weight.
 18. The method of claim 17, further comprisingupdating the updated atmospheric pressure maximum estimation to anintermediate value of the sum of the updated atmospheric pressuremaximum estimation and the updated atmospheric pressure minimumestimation.
 19. The method of claim 18, wherein the controlling of therotation speed of the fan module based on the difference between theupdated atmospheric pressure estimation and the current pressure valuecomprises allowing the rotation speed of the fan module to increase whenthe updated atmospheric pressure estimation is greater than the currentpressure value.
 20. The method of claim 18, wherein the controlling ofthe rotation speed of the fan module based on the difference between theupdated atmospheric pressure estimation and the current pressure valuecomprises allowing the rotation speed of the fan module to decrease orstopping an operation of the fan module when the updated atmosphericpressure estimation is less than the current pressure value.